1. Field of the Invention
This invention relates generally to mechanisms that secure a fabric to a rigid object and, in particular, to a clamping mechanism that, through a mating process, removably fixes a filter fabric to a foraminous concrete form. Although incorporating the use of adhesives, in but a single instance, such are generally exchewed in the instant invention.
2. Discussion of Relevant Art
Throughout the art, numerous methods and techniques have been used to secure fabrics, of varying mesh, to objects such as frames, screens, etcs. Our patent, U.S. Pat. No. 5,466,092 discloses one such method that involves the use of adhesives. Although quite successful, there unfortunately exists the necessity of fixing form-drain filters during inclement weather, such as periods of rain/sleet. During such times, moisture accumulating on form-drain surfaces, although not constituting a major impediment, nonetheless can inhibit adhesion of the adhesive-coated margins of fabric to the form-drain. Thus, it was incumbent upon us to provide a purely physical means of securing the fabric, irrespective of enviromental conditions.
In a patent entitled: FILTER, U.S. Pat. No. 445,223, there is disclosed an elongated frame member that is defined by a U-shaped cross-section. The legs of the member are considerably longer than the base (of the U) because the member is primarily a frame element that, as an expedient, "caps" the edges of the structural backing. The underlying backing does not serve as a concrete construction form. Most significantly, the long legs, necessary for strength and rigidity, cover a goodly number of the mesh holes (Cf.,foramens); a feature we found to be unsatisfactory for our purposes.
U.S. Pat. No. 1,172,724 sets forth a C-shaped (cross-section) clamping member for securing a fabric to a bed frame. This member is a mattress feature known as piping and consists in relatively stiff metallic strips, hence "piping". Although the morphology of the clamp is more desirable for our purposes, the device at issue lacks the mating ability we desire, and achieve, between clamp and form-drain. Further, its ends are curvate, a feature we cannot tolerate with the use of the rigid, straight form-drain.
Similar in style and function to '724 is the clamp shown in U.S. Pat. No. 1,719,532. This clamp is rigid, metallic and essentially curvate, having also a U-form or cross-section. It suffers the same limitations as '724, for our purposes.
A clamping structure consisting of a flexible molding having projecting fasteners is disclosed in U.S. Pat. No. 1,221,444. A molding strip consisting of leather or other flexible materials is multiply cut or diagonally split along its length and nail fasteners are placed therein (perpendicularly) to project at right angles (orthogonally) from the strip. The splits or cuts are then cemented or otherwise resecured to the strip. The purpose of this nail-projecting article is to be self-securable (it is a molding) to another article such a baseboard, furniture, automobile bodies or the like. This could serve as a clamp of sorts, but in '444 no such suggestion is made.
Somewhat analogous to '444, U.S. Pat. No. 2,684,776 relates to a flexable strip of material that contains head-driveable fasteners, such as nails, spaced at predetermined distances by embedment in the strip, which is transparent. After the fasteners are driven, the strip is pulled free, having performed the dual function of workpiece protection (from misdirected blows) and fastener spacing. A significant distinction between the strip (molding) of '776 and our invention is that this strip cannot conceivably serve as a clamp, it merely resembles our invention in the patent drawings.
Our searches of Patent Office records and various catalogs disclosed no other relevant art. We therefore set forth, in this paper, our clamping concept that serves as an alternative to the aforementioned adhesively secured form-drain filter.
3. Incorporation by Reference
For both provision of background, as well as useful details and prior art information, our U.S. patent no. (to be provided upon issue), and previously discussed U.S. Pat. Nos. 445,223 (FIG. 1); U.S. Pat. No. 1,172,724 (FIGS. 3 and 4); U.S. Pat. No. 1,221,444 (FIGS. 1-6); U.S. Pat. No. 1,719,532 (FIGS. 4-6); and U.S. Pat. No. 2,684,776 (FIGS. 1-3 and columns 1 and 2), are hereby incorporated by reference.